GDDM Tweaking

build.gradle

@@ -10,8 +10,10 @@ allprojects {
 subprojects {
     apply plugin: 'java'
 
-    sourceCompatibility = JavaVersion.VERSION_11
+    java {
-    targetCompatibility = JavaVersion.VERSION_11
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
 
     test {
         useJUnitPlatform()

j3270/src/main/java/haus/nightmare/j3270/ui/TerminalPanel.java

@@ -163,10 +163,20 @@ public class TerminalPanel extends JPanel {
                     // IMPORTANT ARCHITECTURE NOTE:
                     // 1. In GDDM Graphic Cursor Mode (3179G / GOCA), mouse events represent graphic light-pen touches.
                     //    Text drag-selection is explicitly suppressed so blue selection boxes do not artifact over graphics.
-                    // 2. In Text Light Pen mode (Alt+L on 3270 formatted screens), clicks toggle selectable fields.
+                    // 2. In Text Light Pen / Selectable Field mode (per IBM Host On-Demand MouseMgr.java / PS3270.java),
+                    //    clicks on detectable fields (faIsSelectable) trigger field selection or cursor select.
                     // 3. In standard alphanumeric mode, click-drag selects text for copy-paste.
                     boolean isGraphic = client.getGocaDecoder() != null && client.getGocaDecoder().isGraphicsCursorActive();
-                    if (isGraphic || lightPenMode) {
+                    boolean isSelectableField = false;
+                    if (sb.isFormatted()) {
+                        int faPos = sb.findFieldAttribute(row * displayCols + col);
+                        if (faPos >= 0) {
+                            int fa = sb.getCell(faPos).fa & 0xFF;
+                            isSelectableField = haus.nightmare.lib3270j.protocol.DS3270Constants.faIsSelectable(fa) &&
+                                                !haus.nightmare.lib3270j.protocol.DS3270Constants.faIsZero(fa);
+                        }
+                    }
+                    if (isGraphic || lightPenMode || isSelectableField) {
                         clearSelection();
                     } else {
                         selectionStartRow = row;
@@ -277,6 +287,25 @@ public class TerminalPanel extends JPanel {
                             return;
                         }
 
+                        // Automatic Light-Pen / Selectable Field detection on mouse click:
+                        // Per IBM Host On-Demand (MouseMgr.java / PS3270.java) and 3270 specifications:
+                        // If the clicked screen location belongs to a detectable field (faIsSelectable and not faIsZero),
+                        // automatically process light-pen / cursor selection (e.g. immediate selection, Enter, or toggling ? -> >).
+                        if (sb.isFormatted()) {
+                            int faPos = sb.findFieldAttribute(clickAddr);
+                            if (faPos >= 0) {
+                                int fa = sb.getCell(faPos).fa & 0xFF;
+                                if (haus.nightmare.lib3270j.protocol.DS3270Constants.faIsSelectable(fa) &&
+                                    !haus.nightmare.lib3270j.protocol.DS3270Constants.faIsZero(fa)) {
+                                    clearSelection();
+                                    if (client.lightPenSelect(clickAddr)) {
+                                        refreshScreen();
+                                        return;
+                                    }
+                                }
+                            }
+                        }
+
                         if (lightPenMode) {
                             clearSelection();
                             sb.setCursorAddress(clickAddr);
@@ -947,8 +976,8 @@ public class TerminalPanel extends JPanel {
                 g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
                 g2.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
 
-                int fontSize = (int) Math.round(ch * 0.95);
+                int fontSize = Math.min((int) Math.round(ch * 0.82), (int) Math.round(cw * 1.45));
-                if (fontSize < 10) fontSize = 10;
+                if (fontSize < 9) fontSize = 9;
                 Font f = (boldTerminalFont != null ? boldTerminalFont : terminalFont).deriveFont((float) fontSize);
                 g2.setFont(f);
                 FontMetrics fm = g2.getFontMetrics();
@@ -1154,10 +1183,11 @@ public class TerminalPanel extends JPanel {
                         Font f = bold ? boldTerminalFont : terminalFont;
                         g2.setFont(f);
                         g2.setColor(fgColor);
+                        int textY = y + fontAscent + Math.max(0, (cellHeight - (fontAscent + fontDescent)) / 2);
                         if (ch < 128) {
-                            g2.drawString(CHAR_STRINGS[ch], x, y + fontAscent);
+                            g2.drawString(CHAR_STRINGS[ch], x, textY);
                         } else {
-                            g2.drawString(String.valueOf(ch), x, y + fontAscent);
+                            g2.drawString(String.valueOf(ch), x, textY);
                         }
                     }
                 }
@@ -1165,8 +1195,8 @@ public class TerminalPanel extends JPanel {
                 // Draw underline
                 if (underline) {
                     g2.setColor(fgColor);
-                    g2.drawLine(x, y + cellHeight - fontDescent,
+                    int ulY = Math.min(y + cellHeight - 1, y + fontAscent + Math.max(0, (cellHeight - (fontAscent + fontDescent)) / 2) + 2);
-                            x + cellWidth - 1, y + cellHeight - fontDescent);
+                    g2.drawLine(x, ulY, x + cellWidth - 1, ulY);
                 }
 
                 // Draw selection highlight

lib3270j/src/main/java/haus/nightmare/lib3270j/datastream/DataStreamProcessor.java

@@ -41,7 +41,7 @@ public class DataStreamProcessor {
 
     // Graphics & Programmed Symbols
     private final haus.nightmare.lib3270j.graphics.ProgramSymbolManager programSymbolManager = new haus.nightmare.lib3270j.graphics.ProgramSymbolManager();
-    private final haus.nightmare.lib3270j.graphics.GraphicsPlane graphicsPlane = new haus.nightmare.lib3270j.graphics.GraphicsPlane(800, 600);
+    private final haus.nightmare.lib3270j.graphics.GraphicsPlane graphicsPlane = new haus.nightmare.lib3270j.graphics.GraphicsPlane(720, 384);
     private final haus.nightmare.lib3270j.graphics.GocaDecoder gocaDecoder = new haus.nightmare.lib3270j.graphics.GocaDecoder(graphicsPlane);
     private final java.io.ByteArrayOutputStream gocaAccumulator = new java.io.ByteArrayOutputStream();
     private int currentGocaSubtype = 0;
@@ -853,6 +853,11 @@ public class DataStreamProcessor {
                                         sfSubId, fieldLen, flags, (orderOffset - pos), orderLen, hexDump.toString().trim()));
 
                                 graphicsPlane.setScreenDimensions(screen.getCols(), screen.getRows());
+                                int targetW = screen.getCols() * 9;
+                                int targetH = screen.getRows() * 16;
+                                if (graphicsPlane.getCanvasWidth() != targetW || graphicsPlane.getCanvasHeight() != targetH) {
+                                    graphicsPlane.resize(targetW, targetH);
+                                }
 
                                 if (flags == 0x80) { // SPAN_FIRST
                                     gocaAccumulator.reset();

lib3270j/src/main/java/haus/nightmare/lib3270j/datastream/QueryReplyBuilder.java

@@ -293,14 +293,36 @@ public class QueryReplyBuilder {
         out.write((Yr_3279_2 >> 16) & 0xFF);
         out.write((Yr_3279_2 >> 8) & 0xFF);
         out.write(Yr_3279_2 & 0xFF);
-        out.write(SW_3279_2);                // AW
+        int charW = getCharWidth();
-        out.write(SH_3279_2);                // AH
+        int charH = getCharHeight();
+        out.write(charW);                    // AW
+        out.write(charH);                    // AH
         int buf = maxCols * maxRows;
         out.write((buf >> 8) & 0xFF);        // buffer size high
         out.write(buf & 0xFF);               // buffer size low
         return out.toByteArray();
     }
 
+    public int getCharWidth() {
+        return SW_3279_2; // 9
+    }
+
+    public int getCharHeight() {
+        // ARCHITECTURAL NOTE ON 3179G GOCA VERTICAL ALIGNMENT & QUERY REPLIES:
+        // Why hardcoding SH = 12 (0x0C) in Character Sets & Usable Area failed in past iterations:
+        // When SDH/AH is declared as 12 (0x0C) in Query Reply, the mainframe host GDDM engine computes
+        // total presentation space as rows * 12 (e.g. 43 * 12 = 516 units, yMax = 257).
+        // GDDM then places the top menu bar at Row 1 (gy = 187..200).
+        // Meanwhile, the client emulator rendered into a 16-pitch grid (43 * 16 = 688 units, yMax = 343).
+        // On a 688-unit canvas, gy = 200 mapped to Row 9.2 (middle of the screen), leaving a massive void above.
+        // When the user clicked on the visual menu drawn at Row 9, the client emitted gy = 189 with cursor at Row 9,
+        // which GDDM rejected as outside its menu hit box (causing terminal alarm beeps).
+        //
+        // Solution: Declare SDH = 16 (0x10) when Vector Graphics is enabled (3179G standard), ensuring host GDDM
+        // and client GraphicsPlane share the exact same 16-pitch presentation space (720x688, yMax = 343).
+        return graphicsMode.isVectorGraphicsEnabled() ? 0x10 : SH_3279_2;
+    }
+
     private byte[] buildAlphaPartitions(int maxRows) {
         int bufSize = screen.getMaxCols() * screen.getMaxRows();
         ByteArrayOutputStream out = new ByteArrayOutputStream(4);
@@ -312,13 +334,16 @@ public class QueryReplyBuilder {
     }
 
     private byte[] buildCharsets() {
+        int charW = getCharWidth();
+        int charH = getCharHeight();
+
         if (graphicsMode.isProgrammedSymbolsEnabled()) {
             // Programmed Symbols mode (3279 PS with LoadPS 0x0A, flags1 = 0xA2 for GE + PS + CGCSGID)
             ByteArrayOutputStream out = new ByteArrayOutputStream(65);
             out.write(0xa2); // flags: GE (0x80), PS/Loadable Charsets (0x20), CGCSGID present (0x02)
             out.write(0x00); // more flags
-            out.write(SW_3279_2); // SDW (9)
+            out.write(charW); // SDW (9)
-            out.write(SH_3279_2); // SDH (12)
+            out.write(charH); // SDH (16 for 3179G, 12 for 3279-2)
             out.write(0x0a); // Load PS format types supported: Format 1 and Format 3
             out.write(0x00); // Load PS device type (high)
             out.write(0x00); // Load PS device type (low)
@@ -343,8 +368,8 @@ public class QueryReplyBuilder {
         ByteArrayOutputStream out = new ByteArrayOutputStream(23);
         out.write(0x82); // flags: GE, CGCSGID present
         out.write(0x00); // more flags
-        out.write(SW_3279_2); // SDW - default char width (9)
+        out.write(charW); // SDW - default char width (9)
-        out.write(SH_3279_2); // SDH - default char height (12)
+        out.write(charH); // SDH - default char height (16 for 3179G, 12 for 3279-2)
         out.write(0x00); // LoadPS format (0x00)
         out.write(0x00);
         out.write(0x00);

lib3270j/src/main/java/haus/nightmare/lib3270j/graphics/GraphicInputBuilder.java

@@ -6,9 +6,14 @@ package haus.nightmare.lib3270j.graphics;
  */
 public class GraphicInputBuilder {
 
-    // 56-byte template mask from IBM Host On-Demand (HODInput.java)
+    // 56-byte template mask from IBM Host On-Demand (HODInput.java).
+    // Note on Structured Field Length (bytes 0-1):
+    // IBM HOD sets bytes 0-1 to 0x00 0x34 (52 decimal). In 3270 GOCA architecture,
+    // the Data Unit Object Control payload is 52 bytes. Overwriting this with 0x00 0x38 (56)
+    // causes the host's 3270 inbound structured field decoder to misalign the trailing AID byte
+    // (0x7D) and cursor address by 4 bytes, causing host GDDM to reject the click with an alarm beep.
     private static final byte[] MASK = new byte[] {
-        0x00, 0x38, 0x0F, 0x0F, 0x00, (byte) 0xC0, 0x00, 0x40,
+        0x00, 0x34, 0x0F, 0x0F, 0x00, (byte) 0xC0, 0x00, 0x40,
         0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x23, 0x00, 0x23, 0x00, 0x00, 0x00, 0x1F, 0x01,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
@@ -60,9 +65,8 @@ public class GraphicInputBuilder {
         byte[] sf = new byte[MASK.length];
         System.arraycopy(MASK, 0, sf, 0, MASK.length);
 
-        // Byte 0-1: Structured Field Length (56 bytes)
+        // Bytes 0-1: Structured Field Length (0x0034 = 52 decimal per IBM HODInput.java / GOCA architecture).
-        sf[0] = (byte) ((MASK.length >> 8) & 0xFF);
+        // Preserved from MASK; do not overwrite with MASK.length (56).
-        sf[1] = (byte) (MASK.length & 0xFF);
 
         // Bytes 16-19: Device correlation class descriptor (0x23, 0x00, 0x23, 0x00)
         // Note: Preserved from MASK per IBM Host On-Demand (HODInput.java); do not overwrite with row/col.

lib3270j/src/main/java/haus/nightmare/lib3270j/graphics/GraphicsPlane.java

@@ -36,14 +36,14 @@ public class GraphicsPlane {
         {-1, -1, -1, -1, -1, -1, -1, -1}                      // 16: Solid
     };
 
-    private int canvasWidth = 800;
+    // 3179G Presentation Space metrics: 9x16 cell pitch (720x384 for Model 2, 720x688 for Model 4)
-    private int canvasHeight = 600;
+    private int screenCols = 80;
+    private int screenRows = 24;
+    private int canvasWidth = 720;
+    private int canvasHeight = 384;
     private int[] rgbBuffer;
     private boolean hasContent = false;
     private long updateCount = 0;
-
-    private int screenCols = 80;
-    private int screenRows = 24;
     private ProgramSymbolManager programSymbolManager;
 
     public void setProgramSymbolManager(ProgramSymbolManager psm) {
@@ -595,20 +595,19 @@ public class GraphicsPlane {
         int fill = (fillColorArgb != 0) ? fillColorArgb : GocaConstants.GOCA_COLORS[0];
         int bg = bgColorArgb;
 
-        // Note / Logic for Future Iterations:
+        // ARCHITECTURAL NOTE ON GOCA BACKGROUND MIX & BLACK AREA FILLING:
-        // In IBM 3179G / GDDM architecture, solid black fills (fillColor = GOCA_COLORS[8] / 0xFF000000,
+        // In GOCA (GA23-0059 / SC31-6805), Color 0 / 8 is the default background/neutral color (Black).
-        // pattern = PT_SOLID / 16) are the standard mechanism used by host applications to ERASE
+        // Background Mix (GSBMX / bgMix):
-        // dropdown menus, dialog boxes, and dynamic regions from the screen.
+        //   - bgMix == 0 or 2 (BMX_DEFAULT / BMX_LEAVE): Leave destination unchanged (Transparent).
-        //
+        //     Fills with default background color (Black) under BMX_LEAVE are transparent and must NOT overwrite pixels.
-        // A prior failed attempt added an 'isTransparentBlack' guard:
+        //     (e.g. ADMOPSLA slide preview selection boxes, where GDDM draws hollow frames with bgMix = 0).
-        //   boolean isTransparentBlack = (fill == GOCA_COLORS[8] || (fill & 0x00FFFFFF) == 0) && (bgMix != MIX_OVER);
+        //   - bgMix == 5 or 1 (BMX_OVER / OVERPAINT): Overwrite background pixels with background color (Opaque).
-        //   if (... && !isTransparentBlack)
+        //     Fills with Black under BMX_OVER are explicit erasure rectangles used to erase closed menus and dialogs
-        // This caused GDDM's menu erasure rectangles (which use fillColor = Black and bgMix = 5) to be
+        //     (e.g. ADMDRAW menu erasure, where GDDM explicitly issues GSBMX 5 before the black fill).
-        // silently skipped and discarded. As a result, closed dropdown menus were never erased, causing
+        boolean isTransparentBlack = ((fill & 0x00FFFFFF) == 0) &&
-        // multiple menus (FILE, DRAW, TRANSFORM) to linger and stack on top of each other permanently.
+                                     (bgMix == GocaConstants.MIX_DEFAULT || bgMix == GocaConstants.MIX_LEAVE || bgMix == 0);
-        //
+
-        // Solid black fills (0xFF000000) must always be rasterized to overwrite and erase previously drawn pixels.
+        if (!isTransparentBlack && pattern != GocaConstants.PT_EMPTY && (pattern != 0 || !drawBoundary)) {
-        if (pattern != GocaConstants.PT_EMPTY && (pattern != 0 || !drawBoundary)) {
             // Find polygon vertical bounds across all points
             int minY = py[0];
             int maxY = py[0];

lib3270j/src/main/java/haus/nightmare/lib3270j/input/InputProcessor.java

@@ -244,7 +244,43 @@ public class InputProcessor {
             return;
         }
 
-        // Enter, PF keys, PA keys: send AID + optional PID + cursor address + modified field data
+        if (aidCode == AID_SELECT) {
+            // 3270 Selector Pen / Light Pen Immediate Selection (AID 0x7E):
+            // Per IBM 3270 Data Stream Architecture (GA23-0059) and IBM Host On-Demand (DS3270.sendAid lines 727-1019):
+            // The inbound data stream consists of:
+            // 1. AID byte (0x7E)
+            // 2. Cursor address (2 bytes)
+            // 3. For each field with MDT=1:
+            //    - SBA order (0x11)
+            //    - Designator character address (faAddr + 1)
+            // CRITICAL: NO FIELD CHARACTER DATA IS TRANSMITTED FOR AID_SELECT!
+            // Sending character data in an AID_SELECT stream violates 3270 protocol and causes the host to reject the selection.
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+            out.write(AID_SELECT);
+
+            byte[] caddr = encodeAddress(screen.getCursorAddress(), screen.getRows(), screen.getCols());
+            out.write(caddr[0] & 0xFF);
+            out.write(caddr[1] & 0xFF);
+
+            if (screen.isFormatted()) {
+                int size = screen.getRows() * screen.getCols();
+                for (int i = 0; i < size; i++) {
+                    ExtendedAttribute ea = screen.getCell(i);
+                    if (ea.isFieldAttribute() && faIsModified(ea.fa & 0xFF)) {
+                        int designatorAddr = (i + 1) % size;
+                        out.write(ORDER_SBA);
+                        byte[] addr = encodeAddress(designatorAddr, screen.getRows(), screen.getCols());
+                        out.write(addr[0] & 0xFF);
+                        out.write(addr[1] & 0xFF);
+                    }
+                }
+            }
+
+            sendAidResponse(out.toByteArray());
+            return;
+        }
+
+        // Enter, PF keys: send AID + optional PID + cursor address + modified field data
         ByteArrayOutputStream out = new ByteArrayOutputStream();
 
         out.write(aidCode);

lib3270j/src/test/java/haus/nightmare/lib3270j/datastream/QueryReplyBuilderTest.java

@@ -132,11 +132,15 @@ public class QueryReplyBuilderTest {
         assertEquals(0x81, replies[3] & 0xFF);
         assertEquals(QR_DDM, replies[4] & 0xFF);
 
-        // Second SF should be Usable Area
+        // Second SF should be Usable Area: 23 bytes (4 bytes header + 19 bytes payload)
         int pos2 = 1 + len1;
         int len2 = ((replies[pos2] & 0xFF) << 8) | (replies[pos2 + 1] & 0xFF);
+        assertEquals(23, len2);
         assertEquals(0x81, replies[pos2 + 2] & 0xFF);
         assertEquals(QR_USABLE_AREA, replies[pos2 + 3] & 0xFF);
+        // Offset 0x15 (21 in SF payload = pos2 + 21): Buffer size high
+        int bufSize = ((replies[pos2 + 21] & 0xFF) << 8) | (replies[pos2 + 22] & 0xFF);
+        assertEquals(80 * 43, bufSize);
     }
 
     @Test

lib3270j/src/test/java/haus/nightmare/lib3270j/input/InputProcessorTest.java

@@ -138,7 +138,7 @@ public class InputProcessorTest {
         byte[] sf = haus.nightmare.lib3270j.graphics.GraphicInputBuilder.buildGraphicInput(100, -50, AID_ENTER, false, false, false);
         assertEquals(56, sf.length);
         assertEquals(0x00, sf[0]);
-        assertEquals(0x38, sf[1]); // Length = 56 bytes (0x0038)
+        assertEquals(0x34, sf[1]); // Length = 52 bytes (0x0034) matching IBM HODInput.java
         assertEquals(0x0F, sf[2]); // SF ID = 0x0F
         assertEquals(0x0F, sf[3]); // SF ID = 0x0F
 
@@ -160,7 +160,7 @@ public class InputProcessorTest {
         );
         assertEquals(56, sfMouse.length);
         assertEquals(0x00, sfMouse[0]);
-        assertEquals(0x38, sfMouse[1]);
+        assertEquals(0x34, sfMouse[1]); // Length = 52 bytes (0x0034) matching IBM HODInput.java
         assertEquals(0x23, sfMouse[16]);
         assertEquals(0x00, sfMouse[17]);
         assertEquals(0x23, sfMouse[18]);
@@ -394,9 +394,9 @@ public class InputProcessorTest {
         // 1 (AID_SF 0x88) + 56 (SF) + 1 (AID_ENTER 0x7D) + 2 (Cursor Addr) + 1 (SBA) + 2 (Field Addr) + 1 (Data 'A') = 64 bytes
         assertEquals(64, result.length);
         assertEquals((byte) AID_SF, result[0]);
-        // SF length = 56 (0x00 0x38)
+        // SF length = 52 (0x00 0x34) per IBM HOD / GOCA specification
         assertEquals(0x00, result[1]);
-        assertEquals(0x38, result[2]);
+        assertEquals(0x34, result[2]);
         // SF ID = 0x0F0F
         assertEquals(0x0F, result[3]);
         assertEquals(0x0F, result[4]);
@@ -418,4 +418,37 @@ public class InputProcessorTest {
         // Trailing field content 'A' at 63
         assertEquals((byte) 0xC1, result[63]);
     }
+
+    @Test
+    public void testAidSelectFramingOmitsFieldData() {
+        // Formatted screen with an unprotected field at 0, modified, containing 'A' and 'B'
+        screen.erase(false);
+        screen.setCellFA(0, (byte) (FA_PRINTABLE | FA_MODIFY));
+        screen.setCellFA(10, (byte) (FA_PRINTABLE | FA_PROTECT));
+        screen.getCell(1).ec = (byte) 0xC1;
+        screen.getCell(1).ucs4 = 'A';
+        screen.getCell(2).ec = (byte) 0xC2;
+        screen.getCell(2).ucs4 = 'B';
+        screen.setCursorAddress(1);
+
+        java.util.concurrent.atomic.AtomicReference<byte[]> sent = new java.util.concurrent.atomic.AtomicReference<>();
+        InputProcessor input = new InputProcessor(screen, translator, null) {
+            @Override
+            protected void sendAidResponse(byte[] data) {
+                sent.set(data);
+            }
+        };
+
+        input.sendAid(AID_SELECT);
+
+        byte[] result = sent.get();
+        assertNotNull(result);
+        // For AID_SELECT (0x7E), the stream consists ONLY of:
+        // 1 byte AID (0x7E) + 2 bytes cursor address + 1 byte SBA (0x11) + 2 bytes designator address = 6 bytes total.
+        // Field character contents ('A', 'B') MUST NOT be sent per IBM 3270 DS architecture!
+        assertEquals(6, result.length);
+        assertEquals((byte) AID_SELECT, result[0]);
+        // SBA order at byte 3
+        assertEquals((byte) ORDER_SBA, result[3]);
+    }
 }